A process and polyimide product formed by the reaction of a bismaleimide with a bis(amidediene) is disclosed wherein the bis(amidediene) is formed by reacting an excess of an acid chloride with 1,4-N,N'-diisoprenyl 2,3,5,6-tetramethy1 benzene

Ottenbrite, Raphael M.

Smith, Joseph G., Jr.

English

NASA Technical Reports Server

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US005200497A 
United States Patent [19] [ii] Patent Number: 5,200,497 
Smith, Jr. et al. [45] Date of Patent: Apr. 6, 1993 
[54] POLYIMIDE FROM BIS(N-1SOPRENYL)S 
OF ARM, DIAMIDES 
[75] Inventors: Joseph G. Smith, Jr., Hampton; 
Raphael M. Ottenbrite, Midlothian, 
both of Va. 
[73] Assignee: The United States of America as 
represented by the Adminstrator, 
National Aeronautics and Space 
Administration, Washington, D.C. 
[21] Appl. No.: 568,128 
[22] Filed: Aug. 16, 1990 
[51] 
[52] 
Int. C l . 5  ............................................ CU8F 222/40 
U.S. c1. .................................... 526/262; 528/170; 
528/32I; 528/322 
[58] Field of Search ................ 526/262; 528/322, 321, 
528/170 
[561 References Cited 
U.S. PATENT DOCUMENTS 
4,593,083 6/1986 Stenzenberger .......... 526/262 
4,822,870 4/1989 Restaino .............................. 526/262 
Primary Examiner-Harold D. Anderson 
Attorney, Agent, or Firm-George F. Helfrich 
A process and polyimide product formed by the reac- 
tion of a bismaleimide with a bis(amidediene) wherein 
the bis(amidediene) is formed by reacting an excess of 
an acid chloride with 1,4-N,N'-diisoprenyl-2,3,5,6-tet- 
ramethyl benzene. 
WI ABSTRACT 
3 Claims, No Drawings 
https://ntrs.nasa.gov/search.jsp?R=19930012844 2020-03-24T07:30:19+00:00Z

5,200,497 
3 4 
-continued 
-CH3 -CH3 
{:yJq*N&:-. where 0 // n is an integer equal -CH3 to or 111 greater -CH3 than R 1; R is \O t 
selected from the group of radicals consisting of 
95% ethanol to the reaction. The solution was concen- 
trated on a rotoevaporator and methanol subsequently 
15 added to the mixture. Dropwise addition of distilled 
water precipitated the crude product. The monomer 
was purified by dissolving in a methanol/acetone sol- 
vent mixture (l:lO), vacuum filtering, and precipitating 
by the dropwise addition of distilled water to afford a 
20 74% yield. 1H NMR (CDCl3) 1.7-1.8 ppm (d,6H), 4.35 
ppm (s,4H), 4.6-5.75 ppm (m,8H), 6.0-6.65 ppm 
C H 3 9 Q W *  
QQ@ 
@@TOQ; NH2 
( d o .  Similar bis(amidediene) monomers were also pre- 
pared using other acid chlorides including benzoyl, 
~ 25 2-naphthoyl, Cphenylbenzoyl, Cnitrobenzoyl, and 2- 
phenoxybenzoyl. The 2-naphthoyl and 2-phenoxybenz- 
oyl functionalities were chosen for their relative size (as 
compared to the phenyl moiety), which should increase 
the concentration of the cisoid configuration of the 
30 diene system. The Cnitrobenzoyl functionality was 
chosen so as to provide a functional group (nitro substit- 
uent) which could be further manipulated chemically to 
prepare some novel bis(amidediene)s. 
The infrared spectrum for these monomers exhibited 
Ar is selected from the group Of radicals COnSiSting Of 35 a strong carbonyl absorption (Amide 1 Band) ranging 
from 1647-1526 cm-1. Conjugation of the amide car- 
bonyl functionality to the aromatic systems resulted in 
absorptions at lower wave numbers. The bis(amidedi- 
ene) monomers were soluble in benzene and chlorinated 
40 hydrocarbons except for the 2-naphthoyl derivative, 
which was insoluble in benzene. The Cnitrophenyl 
derivative was partially soluble in TCE and insoluble in 
ited partial solubility in chlorinated hydrocarbons. 
45 These monomers did not exhibit melting points below 
270' C. BS determined by DSC analysis and elemental 
analyses were within 0.3% of the theoretical values 
with the exception of low carbon values found for the 
methyl, 4-phenylbenzoyl, Cnitrophenyl, and 4- 
50 aminophenyl derivatives which will be further dis- 
cussed hereinafter. 
NO2 
and 
@ H Z Q T  
I chloroform, while the Caminophenyl derivative exhib- 
and 
POLYMERIZATION 
-@ 
DESCRIPTION OF THE PREFERRED Equimolar quantities of the bis(amidediene) and bis- 
EMBODIMENTS 55 maleimide, with hydroquinone added as a radical scav- 
enger, were dissolved in 1,1,2,2-tetrachloroethane 
(TCE) to afford a 25-30% (w/w) solution. The solution Synthesis of 
l,CN,Ndiacetamido-N,Ndiisoprenyl-2,3,5,~tet- wBS stirred at rOOm temperature over- 
night under a nitrogen atmosphere and the reaction ramethyl benzene 
1,4-N,Ndiacetamido-N,Ndiisoprenyl-2,3,5,&tet- 60 temperature then raised to 100'-150' C. and maintained 
ramethyl benzene was prepared by reacting 1,4,-N,N- 
diisoprenyl-2,3,5,&tetramethyl benzene with an excess 
of acetyl chloride in 40 ml of benzene containing 1.3 ml 
of propylene oxide as an acid scavenger. The reaction 
mixture was stirred for 36 hours at room temperature 
while the flask was covered with foil to avoid light 
catalyzed polymerization of the reactants or products. 
Excess acid chloride was destroyed by the addition of 
for -15-36 hours with stirring. During this time, the 
reaction mixture became viscous and was diluted by the 
addition of small quantities of solvent (1-2 ml) from 
time to time to maintain efficient stirring. The resulting 
65 polymer was precipitated by adding the room tempera- 
ture cooled solution, dropwise, to a quantity of diethyl 
ether. The recovered polyimide precipitate was dried 
under vacuum. 
5,200,497 
5 
Inherent viscosities were obtained for 0.5% chloro- 
form solutions at 30" C. +/- 0.5" C. in a Cannon- 
Ubbelohde viscometer. Differential Scanning Calorim- 
etry @SC) was performed on a Dupont model 1090 
instrument at a heating rate of 20" C./min with glass 
transition temperatures (Tg) taken as the inflection 
point of the AT vs temperature curve. Thermogravi- 
metric analysis was performed on a Perkin Elmer In- 
strument (Program Temperature Controller model 
W - 1 ,  Heater Controller and Auto Balance model 
AR-2) on powdered samples at a heating rate of 2.5" 
C./min in nitrogen and air. Spectral data (IR and *H 
NMR) confmed the structure of the products. 
Model Synthesis 
The copolymerization of the bis(amidedienes) with 
bismaleimides occurred by a Diels-Alder reaction as 
determined with NMR on model systems. Model com- 
pounds were prepared by reacting two moles of N-phe- 
nyl maleimide with the bis(amidedienes) in chloroform 
(approximately 30% (w/w) at room temperature and 
with hydroquinone added as a radical scavenger. The 
color of the products ranged from white to an off-white, 
except for the acetyl derivative which was light-tan. 
Elemental analyses were within 0.3% of the theoretical 
values except for the carbon values which were 
0.4-0.9%. 
Infrared absorptions at 1774, 1704, and 1380 cm-1 
observed proved to be characteristic of the imide func- 
tionality. The amide I band (carbonyl stretch) ranged 
from 1647-1619 cm-1. The splitting pattern for the 
cyclohexene ring was different for each compound and 
was very broad and diffuse in the range of 1.35-3.27 
ppm. The absorption for the vinylic proton attached to 
the C-6 carbon of the isoindole type system ranged from 
5.00-5.70 ppm. This signal appeared as a broad doublet 
for the benzoyl, 2-naphthoyl, 4-phenylbenzoyl and 4- 
nitrobenzoyl derivatives. This proton provided a com- 
plex multiplet for the 2-phenoxybenzoyl system due to 
the steric bulk provided by the 2-phenoxybenzoyl sub- 
stituent. 
These amideimide adducts did not exhibit well de- 
fined melting points, but several endo- and exothermic 
transitions observed by DSC suggest that the Diels- 
Alder adducts are undergoing retro cycloaddition reac- 
tions at elevated temperatures (endothermic transitions) 
with subsequent addition reactions of the regenerated 
1,3-diene and dienophile reactants (exothermic transi- 
tions). 
Polymer Preparation 
Polymers were prepared for each of the bis(amidedi- 
ene) and bismaleimide combinations (as set forth in the 
general formula above) by the reaction of stoichiomet- 
ric quantities with hydroquinone added as a radical 
scavenger and utilizing 1,1,2,2-tetrachloroethane (TCE) 
as the solvent. The flask was equipped with a mechani- 
cal stirrer and flushed with nitrogen for 5-10 mhutes. 
Heating to 70"-80" C. for 5-10 minutes dissolved the 
monomers and the solution was allowed to cool to room 
temperature (the preparation of the naphthoyl deriva- 
tized bis(amidediene) monomer required the solution 
temperature to be maintained at 70"-75' C. due to the 
limited solubility of this monomer). The color of the 
polymerization mixtures ranged from yellow to yellow- 
green. 
The polymerizations were carried out at room tem- 
perature overnight with a subsequent increase in tem- 
6 
perature to 100"-150" C., that was maintained for the 
15-36 hours necessary to complete the reaction. The 
increase in reaction temperature allowed for more efi- 
cient stirring of the reaction media by decreasing the 
solution viscosity. Small aliquots of TCE were added to 
the reaction as the viscosity increased to maintain effi- 
cient stirring. 
The polyimides were obtained as either powders or 
lo fibrous materials, depending on the apparent molecular 
weight of the system, and colors ranged from light 
brown to white. These polymers were soluble in N,N- 
dimethylacetamide and chlorinated hydrocarbons, with 
15 the exception of the polymer prepared from the 4- 
aminophenyl derivatized bis(amidediene). This insolu- 
bility is possibly due to the strong intermolecular hy- 
drogen bonding between the amine and imide function- 
20 alities. It was determined from inherent viscosity data 
(0.21-0.81 dL/g) that the polymers are low-to-medium 
molecular weight although the monomer system of the 
present invention does provide higher molecular 
weight materials than those obtained from previously 
reported bis(N-isoprenyl) monomers. This increase in 
molecular weight was attributed to the increase in the 
reactivity of the 1,3-butadienyl system through steric 
effects. Moderate thermal stability was observed by 
30 thermogravimetric analysis with 10% weight loss rang- 
ing from 318'-356" C. and 316"-381' C. in air and he- 
lium, respectively. No weight gain was observed for 
these materials in air. Tg's were obtainable for these 
35 polymers and ranged from 202"-260' C. Films cast from 
chloroform were flexible and creasible for the methyl, 
4-phenylbenzoyl, phenyl, and enitrophenyl deriva- 
tives. 
Although the present invention has been described in 
detail with respect to certain preferred embodiments 
thereof, these embodiments are intended as exemplary 
only and are not to be deemed as exhaustive. There are 
many variations and modifications of the specific details 
45 described herein that will appear readily apparent to 
those skilled in the art in the light of the above teach- 
Accordingly, it is to be understood that, within the 
50 scope of the appended claims, and without departing 
from the spirit and scope of the invention as set forth 
herein, the invention may be practiced other than as 
specifically described. 
What is claimed as new and desired to be secured by 
Letters Patent of the United States is: 
1. A polyimide formed of recurring units of 
25 
4o 
ings. 
55 
7 
5,200,497 
8 
-continued 
I 10 to yield a polymer having recurring units of 
R is selected from the group of radicals consisting of 
0= 
CH3 CH3 0 
20 
NO2 25 - N G j - A +  R 
where 
@&OQ; 30 R is selected from the group of radicals consisting of 
NH2 
and 35 
Ar is selected from the group of radicals consisting of 
40 
45 
NO2 
50 @&oQ; 
lQrso21QJ$l and 
-0- - NH2 
55 and 
2. A method of making an aromatic polyimide by 
combining stoichiometric quantities of a bis(amidedi- 
ene) having the general formula 
Ar is selected from the group of radicals consisting of 
60 
65 
and a bismaleimide having the general formula 
9 
5,200,497 
10 
-continued -continued 
wherein the bis(amidediene) and the bismaleimide 
are combined by dissolving the bis(amidediene) 10 
and bismaleimide in a flask containing 1,1,2,2-tetra- 
chlorethane solvent by heating the flask to 70"-80" 
C., with stirring and under nitrogen, for 5-10 min- 
utes; permitting the solution to cool to room tem- 
perature and maintaining the stirring under a nitro- l5 
gen atmosphere for at least 12 hours; increasing the 
temperature to 100"-150" C., while maintaining this 
sphere; cooling the solution to room temperature; 20 
@lf&07Ql 
CN-*JJ 
NH2 
and the bismdeimide having the formula 
temperature, stirring and under a nitrogen atmo- 0 0 
adding ethyl ether the to solution precipitate dropwise the polymer; to a quantity d filtering of di-
and drying the recovered precipitate under vac- 
3. A polyimide reaction product of a bistamidediene) 25 
4 uum to obtain the polyimide. 0 
and a bismaleimide, the bis(amidediene having the gen- where Ar is selected from the group of radicals consist- 
era1 formula ing of 
30 
where R is selected from the group of radicals consist- 
ing of 
40 
45 * * * * *  
50 
55 
60 
65 


Polyimide from bis(n-isoprenyl)s of aryl diamides

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